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Cheap flights from Portland, Maine to London from $602

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from Portland, Maine to London departing on 1/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Portland, Maine to London

Cheap round-trip flights

Enter your travel dates to find the best prices.
Austrian Airlines Logo
8:40 am - 8:35 pm
PWM
-
LHR
30h 55m1 stop
Austrian Airlines Logo
12:00 pm - 6:50 pm
LHR
-
PWM
11h 50m1 stop
$602Austrian Airlines
Thu, Jan 15 - Thu, Jan 22
United Airlines Logo
2:31 pm - 6:40 am
PWM
-
LHR
11h 09m1 stop
United Airlines Logo
6:50 am - 6:50 pm
LHR
-
PWM
17h 00m2 stops
$628United Airlines
Thu, Jan 15 - Thu, Jan 22
United Airlines Logo
3:12 pm - 10:50 am
PWM
-
LHR
14h 38m2 stops
United Airlines Logo
12:05 pm - 11:30 pm
LHR
-
PWM
16h 25m2 stops
$633United Airlines
Thu, Jan 15 - Thu, Jan 22
United Airlines Logo
6:00 am - 9:20 pm
PWM
-
LHR
10h 20m1 stop
United Airlines Logo
1:25 pm - 6:50 pm
LHR
-
PWM
34h 25m2 stops
$637United Airlines
Wed, Jan 21 - Sun, Jan 25
Air Canada Logo
7:27 pm - 7:10 am
PWM
-
LHR
30h 43m2 stops
Air Canada Logo
1:25 pm - 6:50 pm
LHR
-
PWM
34h 25m2 stops
$640Air Canada
Wed, Jan 21 - Sun, Jan 25
Air Canada Logo
6:00 am - 7:10 am
PWM
-
LHR
20h 10m2 stops
Air Canada Logo
6:00 pm - 6:50 pm
LHR
-
PWM
29h 50m2 stops
$644Air Canada
Sat, Jan 31 - Sat, Feb 7
Delta Logo
2:30 pm - 7:15 am
PWM
-
LHR
11h 45m1 stop
Delta Logo
6:30 am - 10:03 pm
LHR
-
PWM
20h 33m2 stops
$645Delta
Tue, Mar 31 - Tue, Apr 14
Delta Logo
4:50 pm - 1:10 pm
PWM
-
LHR
15h 20m2 stops
Delta Logo
9:55 am - 11:59 pm
LHR
-
PWM
19h 04m2 stops
$649Delta
Tue, Mar 31 - Tue, Apr 14
Austrian Airlines Logo
8:40 am - 9:10 am
PWM
-
LHR
19h 30m1 stop
Austrian Airlines Logo
9:10 am - 11:30 pm
LHR
-
PWM
19h 20m1 stop
$655Austrian Airlines
Sat, Jan 31 - Sat, Feb 7
Austrian Airlines Logo
8:40 am - 8:25 am
PWM
-
LHR
18h 45m1 stop
Austrian Airlines Logo
8:00 am - 6:50 pm
LHR
-
PWM
15h 50m1 stop
$656Austrian Airlines
Thu, Jan 29 - Thu, Feb 5

Austrian Airlines flights from Portland, Maine to London Heathrow Airport

Our best Austrian Airlines deals on Portland, Maine to London Heathrow Airport flight tickets
Austrian Airlines
Jan 15
PWM8:40 amPortland
30h 55m
1 stop
LHR8:35 pmLondon Heathrow
Jan 22
LHR12:00 pmLondon Heathrow
11h 50m
1 stop
PWM6:50 pmPortland
$602
Find similar
Austrian Airlines
Jan 31
PWM8:40 amPortland
19h 30m
1 stop
LHR9:10 amLondon Heathrow
Feb 7
LHR9:10 amLondon Heathrow
19h 20m
1 stop
PWM11:30 pmPortland
$655
Find similar
Austrian Airlines
Jan 29
PWM8:40 amPortland
18h 45m
1 stop
LHR8:25 amLondon Heathrow
Feb 5
LHR8:00 amLondon Heathrow
15h 50m
1 stop
PWM6:50 pmPortland
$656
Find similar

United Airlines flights from Portland, Maine to London Heathrow Airport

Our best United Airlines deals on Portland, Maine to London Heathrow Airport flight tickets
United Airlines
Jan 15
PWM2:31 pmPortland
11h 09m
1 stop
LHR6:40 amLondon Heathrow
Jan 22
LHR6:50 amLondon Heathrow
17h 00m
2 stops
PWM6:50 pmPortland
$628
Find similar
United Airlines
Jan 15
PWM3:12 pmPortland
14h 38m
2 stops
LHR10:50 amLondon Heathrow
Jan 22
LHR12:05 pmLondon Heathrow
16h 25m
2 stops
PWM11:30 pmPortland
$633
Find similar
United Airlines
Jan 21
PWM6:00 amPortland
10h 20m
1 stop
LHR9:20 pmLondon Heathrow
Jan 25
LHR1:25 pmLondon Heathrow
34h 25m
2 stops
PWM6:50 pmPortland
$637
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Portland, Maine to London Heathrow Airport that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated December 18, 2025.
Use the filters below to find and compare flights from Portland, Maine to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/15

8:40 am-8:35 pm

1 stop30h 55m

London Heathrow

Thu 1/22

12:00 pm-6:50 pm

1 stop11h 50m

$602

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/15

2:31 pm-6:40 am

1 stop11h 09m

London Heathrow

Thu 1/22

6:50 am-6:50 pm

2 stops17h 00m

$628

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/15

3:12 pm-10:50 am

2 stops14h 38m

London Heathrow

Thu 1/22

12:05 pm-11:30 pm

2 stops16h 25m

$633

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 1/21

6:00 am-9:20 pm

1 stop10h 20m

London Heathrow

Sun 1/25

1:25 pm-6:50 pm

2 stops34h 25m

$637

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 1/21

7:27 pm-7:10 am

2 stops30h 43m

London Heathrow

Sun 1/25

1:25 pm-6:50 pm

2 stops34h 25m

$640

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sat 1/31

6:00 am-7:10 am

2 stops20h 10m

London Heathrow

Sat 2/7

6:00 pm-6:50 pm

2 stops29h 50m

$644

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 3/31

2:30 pm-7:15 am

1 stop11h 45m

London Heathrow

Tue 4/14

6:30 am-10:03 pm

2 stops20h 33m

$645

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 3/31

4:50 pm-1:10 pm

2 stops15h 20m

London Heathrow

Tue 4/14

9:55 am-11:59 pm

2 stops19h 04m

$649

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sat 1/31

8:40 am-9:10 am

1 stop19h 30m

London Heathrow

Sat 2/7

9:10 am-11:30 pm

1 stop19h 20m

$655

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/29

8:40 am-8:25 am

1 stop18h 45m

London Heathrow

Thu 2/5

8:00 am-6:50 pm

1 stop15h 50m

$656

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to London from

How to get the cheapest flight ticket from Portland, Maine to London Heathrow Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to London Heathrow Airport?

The month of October is, on average, the cheapest month to fly to London Heathrow Airport from Portland, Maine, with most prices found around $752. If you’re not able to fly to London Heathrow Airport in October, then April is your next best option. Flight prices from Portland, Maine to London Heathrow Airport during April average around $778.

What is the cheapest day to depart on your flight to London Heathrow Airport?

Our data shows that Tuesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $659. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $722.

What is the cheapest time of day to depart on your flight to London Heathrow Airport?

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the afternoon. momondo users have found flights departing from Portland, Maine to London Heathrow Airport in the afternoon for as low as $635. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the evening are often more expensive with an average ticket price of $699.

When to book flights from Portland, Maine to London Heathrow Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Portland, Maine to London Heathrow Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Portland, Maine to London Heathrow Airport (PWM to LHR) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Portland, Maine to London Heathrow Airport

Fastest flight time

9h 38m

Direct flights

None
The fastest flight from Portland, Maine to London Heathrow Airport takes 9h 38m
There are no direct flights from Portland, Maine to London Heathrow Airport. There are no popular flight routes from Portland, Maine to London Heathrow Airport.
Search flight deals

  • How far is Portland to London Heathrow by plane?

    The distance between Portland and London Heathrow is about 3170.3 mi. In terms of flight time, this usually takes a little over 9h 38m.

  • When did momondo last update prices for flights from Portland Airport to London Heathrow Airport?

    Prices for flights from Portland Airport to London Heathrow Airport refresh daily.

  • How many operators does momondo search for flights from Portland Airport to London Heathrow Airport?

  • How old do you have to be to fly from Portland Airport to London Heathrow Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Portland Airport to London Heathrow Airport.

  • What documentation or ID do you need to fly to London Heathrow Airport?

    The necessary travel and health documents for your London Heathrow Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Portland, Maine to London Heathrow Airport?

Best airlines flying from Portland, Maine to London Heathrow Airport

Compare and see reviews for airlines that fly from Portland, Maine to London Heathrow Airport with momondo
Airline
Rating
Free Cancellation
Price
United AirlinesPriceFrom $648Free CancellationRating
7.4
9,092 reviews
Search United Airlines flights
DeltaPriceFrom $765Free CancellationRating
7.9
8,005 reviews
Search Delta flights

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Gatwick
Hounslow
Milton Keynes
Dover
Luton
Slough
Guildford
Hayes
Dartford
Stratford-upon-Avon
Crawley
Brentwood
Salisbury
Wembley
Watford
Ilford
Cobham
Folkestone
Romford
Richmond

Why use momondo?

Why should I use momondo to find a flight deal from Portland to London?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to London from Portland.

Can I find flights from Portland to London with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to London from Portland with this policy.

How can momondo help me find flights from Portland to London?

Once you have performed a search for Portland to London flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from Portland to London right now. Can momondo alert me if prices change?

If you are simply researching potential flights to London, momondo offers a useful price alert feature which will track prices for flights to London from Portland and alert you when they change.

An easier way to manage your London Heathrow Airport trip

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